Obstructive sleep apnea syndrome afflicts at least 2 - 4% of adults and is associated with significant morbidity and mortality. Continuous positive airway pressure (CPAP) therapy is the primary treatment for sleep apnea in adults, but non-adherence to CPAP limits its effectiveness. Even with maximal medical therapy, nasal obstruction is common in sleep apnea patients and may hamper both CPAP adherence and efficacy. However, nasal obstruction (turbinate hypertrophy) is surgically correctable, and treatment of nasal obstruction may lead to more successful use of CPAP. The long-term goal of the proposed research is to develop a novel, multi-disciplinary, multi-modal approach to therapy, in order to improve clinically important treatment outcomes for sleep apnea. The short-term objectives of this proposal are to: 1) Quantify the effect of nasal turbinate reduction on the nasal airway;2) Determine whether turbinate reduction increases CPAP use or efficacy;and 3) Determine whether turbinate reduction positively influences CPAP treatment outcomes. We will employ a single-site, randomized, double-blind, sham-placebo-controlled trial to test the hypotheses that turbinate reduction: 1) increases nasal airway cross-sectional area;2) increases mean nightly objective CPAP use;and 3) improves sleep apnea quality of life 3 months after CPAP titration. We will use the radiofrequency turbinate reduction surgical technique, which allows ethical randomization and effective blinding. Three, six, and 12 months after turbinate reduction and CPAP titration we will measure the change in the minimal nasal cross-sectional area, level of CPAP use, and improvement in sleep apnea quality of life. Secondary outcomes will capture this treatment's broader impact on the nose, CPAP, and sleep apnea. If turbinate reduction can be shown to improve sleep apnea outcomes through increased use or efficacy of CPAP therapy, this trial will demonstrate the value and effectiveness of a novel, multi- disciplinary, combined medical-surgical approach to the management of obstructive sleep apnea syndrome.